On April 17, 2013, the town of West, Texas was in the midst of a devastating tragedy, when a fire and massive explosion demolished West Fertilizer Company, causing the deaths of 15 people and injuring approximately 200 others. The fire and explosion occurred in the facility’s wooden warehouse, which was filled with wood framed bins and housed 60 tons of ammonium nitrate fertilizer. The explosion registered as a 2.1 earthquake and could be felt for up to 45 miles away. As many as 60 homes and businesses were destroyed in the blast.

The West Fertilizer storage building, which was built in the early 1960’s, was not equipped with fire sprinklers. In addition, sprinklers were not required for the facility, as Texas does not have a statewide fire code. In response to the incident, Texas State Fire Marshal, Chris Connealy, has focused efforts on implementing a state fire code and has stated, “Along with the National Fire Protection Association, we’re trying to do everything we can to reinforce and create new best practices to avoid another situation like what happened in West.”

The Road Forward

The US Chemical Safety Board (CSB) has been investigating this tragedy for the past year and in its preliminary findings estimates that the incident has resulted in over $230 million in damages. While the cause of the fire remains undetermined, the CSB stated that, “the explosion resulted from an intense fire, which detonated the ammonium nitrate stored in the building.”

The CSB has been working with other US agencies; such as the National Fire Protection Association (NFPA), the Environmental Protection Agency (EPA), and the Occupational Health and Safety Administration (OSHA), to learn more about the West tragedy and to develop codes and standards that will help prevent future incidents. In addition, the NFPA Technical Committee on Hazardous Chemicals formed the Ammonium Nitrate Task Group, which has been revising current NFPA codes that address the safe storage and handling procedures for ammonium nitrate.

Because of its unique chemical hazards, ammonium nitrate already has its own chapter (Chapter 11) in NFPA 400 Hazardous Materials Code, which provides requirements relative to the storage, use and protection of these materials inside and outside of buildings. The chemical comes in different forms, so the requirements for the safe storage and handling of it can vary accordingly. According to Nancy Pearce, staff liaison for NFPA 400, “Ammonium nitrate has unique properties that make it more of a challenge…it can be very innocuous and no problem whatsoever. But when you have fire and confinement, that’s when you can possibly get deflagration and detonation. Situations can occur that can make it more hazardous than we had expected it to be. The committee is currently learning more about ammonium nitrate and any new requirements needed for its different forms.”

The Ammonium Nitrate Task Group plans to release the proposed first revision of Chapter 11 for public comment no later than May. We will be sure to monitor the developments to NFPA 400 and provide updates as they become available.